In applications for rocket motors, and especially for rocket motors used to lift earth orbit payloads, a primary concern is the amount of thrust provided for a given amount of fuel consumption, i.e, the specific fuel consumption for a given propulsion device. Specifically, in the various nozzles used in propulsion devices that consume chemical fuel stocks, it would be advantageous to increase the momentum transferred to the rocket nozzles from the combusted fuels, in order to increase thrust of the device. And, although some types of steady flow ejectors have been documented and sometimes used to augment the thrust created by a propulsion device by entraining ambient air into the exhaust stream at the nozzle exit, such devices are, for the most part, not particularly efficient. Many prior art thrust augmentors employ a configuration wherein the primary flow injector is surrounded by the secondary flow at the point of injection. Other prior art thrust augmenters rely on the injection of primary flow through the duct wall through holes, a circumferential passage, or a series of passages, in such a fashion as to cause the primary flow to hug the wall between the secondary flow and the passage wall upstream of the nozzle throat. Also, some prior art thrust augmentation injectors use both internal injection and wall injection. However, many of the prior art thrust augmentors required a containment passageway for the fluid mixing and momentum transfer step. So, although various methods and structures have been provided for augmenting thrust in rocket nozzles, in so far as is known to me, conventional designs known heretofore have not provided for induction of secondary flow in a manner wherein the primary thrust flow from the rocket nozzle(s) surrounds an induced secondary flow downstream of the nozzle throat.
In short, conventional thrust augmentation design for propulsion devices, and in particular, for earth or air launched propulsive devices, has not matched the developments in rocket motor design and reliability. For the most part, conventional rocket designs currently in use have ignored the use of a thrust augmentation component. Thus, it would be desirable to provide an improved propulsion device, and in particular, an improved rocket booster design, that utilizes an efficient thrust augmentation device to improve fuel efficiency, and thus, improve payload performance. Alternately, it would be desirable to enable the use of smaller rocket motors, or even fewer rocket stages, or with smaller rockets having smaller motors and smaller fuel and oxidant tanks, than currently necessary in accomplishing the lift of equivalent payloads.